Late stage at diagnosis is a major factor accounting for survival differences between European countries for several cancers (Gatta et al, 2000; Sant et al, 2003, 2007). For some cancers, for example breast cancer, late stage at diagnosis has been shown to contribute to the difference in survival between rich and poor (Downing et al, 2007) and black and white women (Jack et al, 2009).
Patient delay in presenting for medical help after symptom discovery is likely to contribute to late stage at diagnosis. Low cancer awareness (which may include knowledge or beliefs about cancer symptoms, risk of developing cancer, risk factors, effectiveness of treatment or effectiveness of strategies for early detection) is a risk factor for patient delay (Ramirez et al, 1999; MacDonald et al, 2004).
In 2003, the Department of Health commissioned a systematic review of evidence about factors influencing delay in cancer diagnosis. While this was not its main focus, it included studies examining effectiveness of interventions to reduce patient delays in cancer diagnosis (MacDonald et al, 2004). It concluded that there had been little research in this area, but that public cancer awareness campaigns had been associated with some improvements in awareness and diagnosis of cancer, but that the long-term benefits were unclear.
The lack of evidence about the effectiveness of interventions to promote cancer awareness and early presentation is hampering development of policy and local action. The aim of this study was to examine the evidence of effectiveness of interventions to raise cancer awareness and promote early presentation with cancer symptoms to inform policy and future research.
We searched the peer-reviewed literature published in English for studies examining the effectiveness of interventions to increase cancer awareness or promote early presentation. We searched the Cochrane Library, Medline, EMBASE and PsychINFO from 2000 to November 2008 (see Appendix A online for search strategy). Two reviewers identified relevant studies from titles and abstracts; a third reviewer resolved disagreements. We checked the reference lists of identified reports for further relevant studies.
Study selection criteria
We included studies examining interventions in any population except those targeting only people at high genetic risk or aiming to increase cancer awareness in health professionals exclusively. We searched for studies examining effectiveness of two types of intervention:
Interventions delivered to identified individuals recruited to a study, which attempted to collect outcome data from those individuals after the intervention; for example a one-to-one interaction with a health professional or a leaflet given or posted to an identified individual (‘individual-level interventions’).
Interventions delivered to communities in which researchers did not control or identify which individual received the intervention, for example media campaigns, leaflets distributed indiscriminately at a health club, street stalls with posters and leaflets to promote early presentation (‘community-level interventions’).
For individual-level interventions, we searched for randomised controlled trials in which the comparator was placebo, no intervention or usual care. We excluded studies comparing two different interventions or variants of an intervention.
For community-level interventions, we searched for controlled trials (with contemporaneous controls, randomised or non-randomised, with comparator no intervention) and uncontrolled studies that collected data on outcomes before and after the intervention. This was to acknowledge that evaluating community-level interventions in randomised controlled trials is difficult and that policy on implementation of these is often made on the basis of less rigorous evaluations.
We categorised each type of study by whether the outcome related to cancer awareness or early presentation. We included studies with any one of the following cancer awareness outcomes: knowledge or beliefs about cancer symptoms, what to look for when detecting a change that might be cancer, risk of cancer, cancer risk factors, effectiveness of cancer treatment if given early, natural history or prognosis of cancer, attitudes towards early detection behaviours and help seeking or confidence to detect a change that might be cancer. We included studies with any one of the following outcomes that might reflect early presentation: time from symptom discovery to presentation or diagnosis, stage of disease at diagnosis or survival/mortality.
We excluded studies examining exclusively any of the following outcomes: knowledge of or beliefs about nature of treatment for cancer, cancer screening or checking behaviours (for example checking breasts, testicles or skin); health-checking behaviour (for example frequency of or competency in breast, testicular or skin self-examination); intentions to take up screening or screening uptake. We excluded studies with composite outcomes including the outcomes of interest, where these were not reported separately.
We also excluded studies in which the only post-intervention outcome measure was taken on the same day the intervention was delivered (see Appendix B online for summary of inclusion and exclusion criteria).
Two reviewers independently extracted data from all papers identified as potentially relevant onto a data extraction form (Appendix C online). Two reviewers independently applied the inclusion criteria and a third reviewer resolved disagreements.
The quality of randomised controlled trials eligible for inclusion in the review was scored using a methodology checklist developed previously by members of the review team (Goldsmith et al, 2006) (Appendix D online provides the form used by reviewers to measure quality). Each criterion on the checklist was assessed as well covered, adequately addressed, poorly addressed, not reported or not applicable. The methodological quality of each study was then rated as: ++ (all or most of the criteria have been fulfilled), + (some of the criteria have been fulfilled) or − (few or no criteria have been fulfilled). We did not formally score quality of studies of community-level interventions.
We conducted non-quantitative synthesis of evidence by preparing tables summarising the results of studies for each of the main outcomes of interest.
The search strategy identified 2557 abstracts. Of these, 90 were identified as meeting the criteria and we obtained full text versions of these reports. We subsequently found that 42 of these were not relevant. We excluded three out of the remaining 48 reports because the outcomes did not meet the inclusion criteria. This left 35 studies of individual-level interventions and 10 of community-level interventions. From the individual-level interventions, we excluded 18 because outcomes were measured on the same day as the delivery of the intervention, 7 because they were not randomised controlled trials and 5 because the studies compared interventions with other interventions, rather than no intervention or usual care.